diff --git a/HISTORY.rst b/HISTORY.rst
index 44bfc4b..95931c4 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -1,6 +1,14 @@
 History
 =======
 
+0.14.0.dev0: 2019-07-01
+-----------------------
+
+- Dropped winrm support. The kerberos context is now attached to response
+  objects so applications like winrm can be implemented external to
+  requests-kerberos.
+- Corrected a concurrency issue exposed by threaded applications.
+
 0.12.0: 2017-12-20
 ------------------------
 
diff --git a/requests_kerberos/__init__.py b/requests_kerberos/__init__.py
index 63c7db5..0b3c757 100644
--- a/requests_kerberos/__init__.py
+++ b/requests_kerberos/__init__.py
@@ -22,4 +22,4 @@
 
 __all__ = ('HTTPKerberosAuth', 'MutualAuthenticationError', 'REQUIRED',
            'OPTIONAL', 'DISABLED')
-__version__ = '0.13.0.dev0'
+__version__ = '0.14.0.dev0'
diff --git a/requests_kerberos/kerberos_.py b/requests_kerberos/kerberos_.py
index c248ada..c1371d7 100644
--- a/requests_kerberos/kerberos_.py
+++ b/requests_kerberos/kerberos_.py
@@ -185,7 +185,7 @@ def __init__(
         self.cbt_binding_tried = False
         self.cbt_struct = None
 
-    def generate_request_header(self, host, request=None, response=None, is_preemptive=False):
+    def generate_request_header(self, response, host, request=None, is_preemptive=False):
         """
         Generates the GSSAPI authentication token with kerberos.
 
@@ -262,7 +262,7 @@ def authenticate_user(self, response, **kwargs):
         host = urlparse(response.url).hostname
 
         try:
-            auth_header = self.generate_request_header(host, response=response)
+            auth_header = self.generate_request_header(response, host)
         except KerberosExchangeError:
             # GSS Failure, return existing response
             return response
@@ -426,13 +426,32 @@ def deregister(self, response):
         """Deregisters the response handler"""
         response.request.deregister_hook('response', self.handle_response)
 
+    def wrap_winrm(self, host, message):
+        raise NotImplementedError(
+            "WinRM encryption is no longer supported. The established "
+            "kerberos is now made available on the returned response objects "
+            "with the attribute named 'requests_kerberos_context' so WinRM "
+            "and other similar applications can be implemented external to "
+            "requests_kerberos."
+        )
+
+    def unwrap_winrm(self, host, message, header):
+        raise NotImplementedError(
+            "WinRM encryption is no longer supported. The established "
+            "kerberos is now made available on the returned response objects "
+            "with the attribute named 'requests_kerberos_context' so WinRM "
+            "and other similar applications can be implemented external to "
+            "requests_kerberos."
+        )
+
+
     def __call__(self, request):
         if self.force_preemptive and not self.auth_done:
             # add Authorization header before we receive a 401
             # by the 401 handler
             host = urlparse(request.url).hostname
 
-            auth_header = self.generate_request_header(host, request=request, is_preemptive=True)
+            auth_header = self.generate_request_header(None, host, request=request, is_preemptive=True)
 
             log.debug("HTTPKerberosAuth: Preemptive Authorization header: {0}".format(auth_header))
 
diff --git a/tests/test_requests_kerberos.py b/tests/test_requests_kerberos.py
index 0f1c13b..69092c1 100644
--- a/tests/test_requests_kerberos.py
+++ b/tests/test_requests_kerberos.py
@@ -115,7 +115,7 @@ def test_generate_request_header(self):
             host = urlparse(response.url).hostname
             auth = requests_kerberos.HTTPKerberosAuth()
             self.assertEqual(
-                auth.generate_request_header(host, response=response),
+                auth.generate_request_header(response, host),
                 "Negotiate GSSRESPONSE"
             )
             clientInit_complete.assert_called_with(
@@ -138,7 +138,7 @@ def test_generate_request_header_init_error(self):
             host = urlparse(response.url).hostname
             auth = requests_kerberos.HTTPKerberosAuth()
             self.assertRaises(requests_kerberos.exceptions.KerberosExchangeError,
-                auth.generate_request_header, host, response=response,
+                auth.generate_request_header, response, host
             )
             clientInit_error.assert_called_with(
                 "HTTP@www.example.org",
@@ -160,7 +160,7 @@ def test_generate_request_header_step_error(self):
             host = urlparse(response.url).hostname
             auth = requests_kerberos.HTTPKerberosAuth()
             self.assertRaises(requests_kerberos.exceptions.KerberosExchangeError,
-                auth.generate_request_header, host, response=response,
+                auth.generate_request_header, response, host
             )
             clientInit_complete.assert_called_with(
                 "HTTP@www.example.org",
@@ -568,7 +568,7 @@ def test_generate_request_header_custom_service(self):
             response.headers = {'www-authenticate': 'negotiate token'}
             host = urlparse(response.url).hostname
             auth = requests_kerberos.HTTPKerberosAuth(service="barfoo")
-            auth.generate_request_header(host, response=response),
+            auth.generate_request_header(response, host)
             clientInit_complete.assert_called_with(
                 "barfoo@www.example.org",
                 gssflags=(
@@ -633,7 +633,7 @@ def test_principal_override(self):
             response.headers = {'www-authenticate': 'negotiate token'}
             host = urlparse(response.url).hostname
             auth = requests_kerberos.HTTPKerberosAuth(principal="user@REALM")
-            auth.generate_request_header(host, response=response)
+            auth.generate_request_header(response, host)
             clientInit_complete.assert_called_with(
                 "HTTP@www.example.org",
                 gssflags=(
@@ -651,7 +651,7 @@ def test_realm_override(self):
             response.headers = {'www-authenticate': 'negotiate token'}
             host = urlparse(response.url).hostname
             auth = requests_kerberos.HTTPKerberosAuth(hostname_override="otherhost.otherdomain.org")
-            auth.generate_request_header(host, response=response)
+            auth.generate_request_header(response, host)
             clientInit_complete.assert_called_with(
                 "HTTP@otherhost.otherdomain.org",
                 gssflags=(